Ladder



FIG. 1 is a perspective view of a ladder, showing our new design;

FIG. 2 is a right-side elevation view thereof;

FIG. 3 is a top plan view thereof;

FIG. 4 is a bottom plan view thereof;

FIG. 5 is a front elevational view thereof; and,

FIG. 6 is a rear elevational view thereof. 

CLAIM The ornamental design for a ladder, as shown and described. 